/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.visitor;

import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This InstructionVisitor lets a given <code>ClassVisitor</code> visit all classes involved in any <code>.class</code>
 * constructs that it visits.
 * <p>
 * Note that before JDK 1.5, <code>.class</code> constructs are actually compiled differently, using
 * <code>Class.forName</code> constructs.
 *
 * @author Eric Lafortune
 */
public class DotClassClassVisitor extends SimplifiedVisitor implements InstructionVisitor, ConstantVisitor {
    private final ClassVisitor classVisitor;

    /**
     * Creates a new ClassHierarchyTraveler.
     * 
     * @param classVisitor the <code>ClassVisitor</code> to which visits will be delegated.
     */
    public DotClassClassVisitor(ClassVisitor classVisitor) {
        this.classVisitor = classVisitor;
    }

    // Implementations for InstructionVisitor.

    public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset,
        Instruction instruction) {}

    public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset,
        ConstantInstruction constantInstruction) {
        byte opcode = constantInstruction.opcode;

        // Could this instruction be a .class construct?
        if (opcode == InstructionConstants.OP_LDC || opcode == InstructionConstants.OP_LDC_W) {
            clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
        }
    }

    // Implementations for ConstantVisitor.

    public void visitAnyConstant(Clazz clazz, Constant constant) {}

    public void visitClassConstant(Clazz clazz, ClassConstant classConstant) {
        // Visit the referenced class from the .class construct.
        classConstant.referencedClassAccept(classVisitor);
    }
}
